Hillary Clinton said Thursday that the fatal EgyptAir crash that killed 66 people "does appear that it was an act of terrorism" and that it reinforced "the need for American leadership."

"But, once again, it shines a very bright light on the threats that we face from organized terror groups," the Democratic presidential front-runner told Chris Cuomo on CNN. "ISIS, of course, but then there are other networks of terrorists that have to be hunted down and defeated."

The jetliner, bound from Paris to Cairo, crashed in the Mediterranean Sea early Thursday after swerving wildly in flight, authorities said. Egyptian officials said it may have been a terrorist attack.

"It reinforces the need for American leadership, for the kind of smart steady leadership that only America can provide — working with our allies, partners, friends in Europe, the Middle East and elsewhere," Clinton said. "We have to have a concerted effort that brings to bear both domestic resources, sharing of intelligence, take a hard look at airport security one more time.

"Whatever needs to be done must be done."

The former first lady said that a unified approach was even more critical now because "the world depends on air travel.

"We can't allow it to be interrupted or have people be intimidated and to continue to take the fight — although it needs to be more intensified against ISIS from where it is running its operations in Syria and Iraq."